US3349191A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Talk-off protection for in-band telephone signaling systems
Assignee: AT&T Inc
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Filing: 1965-01-07
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Granted: 1967-10-24
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Expires: 1985-01-07
Abstract
No abstract record available.
Inventors
- 👤 Mann Henry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:17
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/44; H04Q1/444; H04Q1/446
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
194 words
IN A TELEPHONE SYSTEM FOR SENDING COMPLEX VOICEFREQUENCY MESSAGE WAVES OCCUPYING A PREDETERMINED FREQUENCY BAND OVER A TELEPHONE TRUNK FROM A TRAMSITTING TERMINAL TO A RECEIVING TERMINAL, MEANS AT SAID TRANSMITTING TERMINAL TO SEND A SUBSTANTIALLY SIGNAL-FREQUENCY TONE OVER SAID TURNK TO SAID RECEIVING TERMINAL TO SIGNAL AND IDLE TRUNK CONDITION, MEANS AT SAID RECEIVING TERMINAL TO COMPARE THE RECEIVED ENERGY AT THE FREQUENCY OF SAID TONE TO THE RECEIVED ENERGY IN THE REMAINDER OF SAID BAND, MEANS AT SAID RECEIVING TERMINAL TO GENERATE AN IDLE TRUNK INDICATION WHEN THE RATIO OF THE RECEIVED ENERGY AT THE FREQUENCY OF SAID TONE TO THE RECEIVED ENERGY IN THE REMAINDER OF SAID BAND EXCEEDS A PREDETERMINED LEVEL, A BAND-ELIMINATION FILTER ADAPTED TO BLOCK TRANSMISSION OF ENERGY A THE FREQUENCY OF SAID TONE, MANS AT SAID TRANSMITTING TERMINAL TO COMPARE THE ENERGY IN VOICE-FREQUENCY MESSAGE WAVES AT THE FREQUENCY OF SID TONE TO THE ENERGY IN THE SAME VOICE-FREQUENCY MESSAGE WAVES IN THE REMAINDER OF SAID BAND, AND MEANS AT SAID TRAMSITTING TERMINAL TO INSERT SAID BAND-ELIMINATION FILTER TO PREVENT TRANSMISSION TO SAID RECEIVING TERMINAL OF ENERGY IN VOICEFREQUENCY MESSAGE WAVES AT THE FREQUENCY OF SAID TONE
Claim 2
Dependent Claim
194 words
IN A TELEPHONE SYSTEM FOR SENDING COMPLEX VOICEFREQUENCY MESSAGE WAVES OCCUPYING A PREDETERMINED FREQUENCY BAND OVER A TELEPHONE TRUNK FROM A TRAMSITTING TERMINAL TO A RECEIVING TERMINAL, MEANS AT SAID TRANSMITTING TERMINAL TO SEND A SUBSTANTIALLY SIGNAL-FREQUENCY TONE OVER SAID TURNK TO SAID RECEIVING TERMINAL TO SIGNAL AND IDLE TRUNK CONDITION, MEANS AT SAID RECEIVING TERMINAL TO COMPARE THE RECEIVED ENERGY AT THE FREQUENCY OF SAID TONE TO THE RECEIVED ENERGY IN THE REMAINDER OF SAID BAND, MEANS AT SAID RECEIVING TERMINAL TO GENERATE AN IDLE TRUNK INDICATION WHEN THE RATIO OF THE RECEIVED ENERGY AT THE FREQUENCY OF SAID TONE TO THE RECEIVED ENERGY IN THE REMAINDER OF SAID BAND EXCEEDS A PREDETERMINED LEVEL, A BAND-ELIMINATION FILTER ADAPTED TO BLOCK TRANSMISSION OF ENERGY A THE FREQUENCY OF SAID TONE, MANS AT SAID TRANSMITTING TERMINAL TO COMPARE THE ENERGY IN VOICE-FREQUENCY MESSAGE WAVES AT THE FREQUENCY OF SID TONE TO THE ENERGY IN THE SAME VOICE-FREQUENCY MESSAGE WAVES IN THE REMAINDER OF SAID BAND, AND MEANS AT SAID TRAMSITTING TERMINAL TO INSERT SAID BAND-ELIMINATION FILTER TO PREVENT TRANSMISSION TO SAID RECEIVING TERMINAL OF ENERGY IN VOICEFREQUENCY MESSAGE WAVES AT THE FREQUENCY OF SAID TONE
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-10-23 | 1971-04-24 | 1971-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-10-23 | 1975-04-24 | 1975-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-10-23 | 1979-04-24 | 1979-10-24 | $7700.00 | Window Closed / Lapsed |